linux-kernel - RE: [PATCH v3 1/1] usb: cdc-acm: handle unlinked urb in acm read callback

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <08C00E7DCA84054D93A5BD962777345A0349F9CC@shsmsx102.ccr.corp.intel.com>
Date:	Wed, 20 Jan 2016 07:08:51 +0000
From:	"Tang, Jianqiang" <jianqiang.tang@...el.com>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
CC:	"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"stable@...r.kernel.org" <stable@...r.kernel.org>,
	Lu Baolu <baolu.lu@...ux.intel.com>,
	Oliver Neukum <oliver@...kum.org>
Subject: RE: [PATCH v3 1/1] usb: cdc-acm: handle unlinked urb in acm read
 callback

Hi Greg,

   Sorry to disturb you although I know you are very busy  :) 
   One question is about this patch, does the patch already in the process of merge into kernel?
   Or need modify still? 

Thanks a lot!

-----Original Message-----
From: linux-usb-owner@...r.kernel.org [mailto:linux-usb-owner@...r.kernel.org] On Behalf Of Lu Baolu
Sent: Wednesday, December 30, 2015 12:59 PM
To: Oliver Neukum <oliver@...kum.org>; Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: linux-usb@...r.kernel.org; linux-kernel@...r.kernel.org; Lu Baolu <baolu.lu@...ux.intel.com>; Tang, Jianqiang <jianqiang.tang@...el.com>; stable@...r.kernel.org
Subject: [PATCH v3 1/1] usb: cdc-acm: handle unlinked urb in acm read callback

In current acm driver, the bulk-in callback function ignores the URBs unlinked in usb core.

This causes unexpected data loss in some cases. For example, runtime suspend entry will unlinked all urbs and set urb->status to -ENOENT even those urbs might have data not processed yet.
Hence, data loss occurs.

This patch lets bulk-in callback function handle unlinked urbs to avoid data loss.

Signed-off-by: Tang Jian Qiang <jianqiang.tang@...el.com>
Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
Cc: stable@...r.kernel.org
Acked-by: Oliver Neukum <oneukum@...e.com>
---
 drivers/usb/class/cdc-acm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

change log:
v1->v2:
add Acked-by: Oliver Neukum <oneukum@...e.com>.

v2->v3:
add the change log.

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 26ca4f9..8cd193b 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -428,7 +428,8 @@ static void acm_read_bulk_callback(struct urb *urb)
 		set_bit(rb->index, &acm->read_urbs_free);
 		dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n",
 							__func__, status);
-		return;
+		if ((status != -ENOENT) || (urb->actual_length == 0))
+			return;
 	}
 
 	usb_mark_last_busy(acm->dev);
--
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@...r.kernel.org More majordomo info at  http://vger.kernel.org/majordomo-info.html